<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <!--Converted with LaTeX2HTML 2002-2-1 (1.71) original version by: Nikos Drakos, CBLU, University of Leeds * revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan * with significant contributions from: Jens Lippmann, Marek Rouchal, Martin Wilck and others --> <HTML> <HEAD> <TITLE>B.1.1.2 Optional segment header records</TITLE> <META NAME="description" CONTENT="B.1.1.2 Optional segment header records"> <META NAME="keywords" CONTENT="GMT_Docs"> <META NAME="resource-type" CONTENT="document"> <META NAME="distribution" CONTENT="global"> <META NAME="Generator" CONTENT="LaTeX2HTML v2002-2-1"> <META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css"> <LINK REL="STYLESHEET" HREF="GMT_Docs.css"> <LINK REL="previous" HREF="node175.html"> <LINK REL="up" HREF="node174.html"> <LINK REL="next" HREF="node177.html"> </HEAD> <BODY bgcolor="#ffffff"> <!--Navigation Panel--> <A NAME="tex2html5117" HREF="node177.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A> <A NAME="tex2html5111" HREF="node174.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A> <A NAME="tex2html5107" HREF="node175.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A> <A NAME="tex2html5113" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A> <A NAME="tex2html5115" HREF="node255.html"> <IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index" SRC="index.png"></A> <BR> <B> Next:</B> <A NAME="tex2html5118" HREF="node177.html">B.1.2 Binary tables</A> <B> Up:</B> <A NAME="tex2html5112" HREF="node174.html">B.1.1 ASCII tables</A> <B> Previous:</B> <A NAME="tex2html5108" HREF="node175.html">B.1.1.1 Optional file header</A> <B> <A NAME="tex2html5114" HREF="node1.html">Contents</A></B> <B> <A NAME="tex2html5116" HREF="node255.html">Index</A></B> <BR> <BR> <!--End of Navigation Panel--> <H3><A NAME="SECTION001911200000000000000"> B.1.1.2 Optional segment header records</A> </H3> When dealing with time- or (<I>x,y</I>)-series it is usually convenient to have each profile in separate files. However, this may sometimes prove impractical due to large numbers of profiles. An example is files of digitized lineations where the number of individual features may range into the thousands. One file per feature would in this case be unreasonable and furthermore clog up the directory. <A NAME="tex2html1613" HREF="http://gmt.soest.hawaii.edu"><B>GMT</B></A> provides a mechanism for keeping more than one profile in a file. Such files are called <I>multiple segment files</I> and are identical to the ones just outlined except that they have subheaders interspersed with data records that signal the start of a segment. The subheaders may be of any format, but all must have the same character in the first column. When using such files, you must specify the <B>-m</B> option. The unique character is by default '<IMG WIDTH="16" HEIGHT="29" ALIGN="MIDDLE" BORDER="0" SRC="img11.png" ALT="$>$">', but you can override that by appending your chosen character to the M option. E.g., <B>-mH</B> will look for subheaders starting with H, whereas <B>-m'*'</B> will check for asterisks (The quotes are necessary since * has special meaning to <I>UNIX</I>). Some programs such as <A NAME="tex2html1614" HREF="../man/psxy.html"><I><B>psxy</B></I></A><A NAME="28988"></A> will examine the subheaders to see if they contain <B>-W</B> and <B>-G</B> options for specifying pen and fill attributes for individual segments, <B>-Z</B> to change color via a cpt-file, or <B>-L</B> for label specifications. These settings (and occasionally others) will override the corresponding command line options. <P> <HR> <!--Navigation Panel--> <A NAME="tex2html5117" HREF="node177.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A> <A NAME="tex2html5111" HREF="node174.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A> <A NAME="tex2html5107" HREF="node175.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A> <A NAME="tex2html5113" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A> <A NAME="tex2html5115" HREF="node255.html"> <IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index" SRC="index.png"></A> <BR> <B> Next:</B> <A NAME="tex2html5118" HREF="node177.html">B.1.2 Binary tables</A> <B> Up:</B> <A NAME="tex2html5112" HREF="node174.html">B.1.1 ASCII tables</A> <B> Previous:</B> <A NAME="tex2html5108" HREF="node175.html">B.1.1.1 Optional file header</A> <B> <A NAME="tex2html5114" HREF="node1.html">Contents</A></B> <B> <A NAME="tex2html5116" HREF="node255.html">Index</A></B> <!--End of Navigation Panel--> <ADDRESS> Paul Wessel 2010-01-14 </ADDRESS> </BODY> </HTML>
